Allah says in the Holy Qur'an:
"O People, eat from the land what is permitted and good and do not follow in the footsteps of Shaitan, for he is an open enemy to you." (al Baqarah, 2:168).
Since food and drink are essential for the survival of humanity, Allah has given clear guidelines on what can and cannot be consumed. In addition we have also been instructed in manners and behaviour of eating. Thus eating and drinking becomes a way by which a Muslim remembers the bounties of Allah and by observing the rules of Shariah, he also shows his commitment to his religion.
Furthermore, Allah has made the habit of eating an important factor in establishing social unity. He has encouraged the sharing of food with each other and stressed the merits of giving food to the poor and needy. This becomes obligatory when certain sins are committed, for which the Kaffara or penalty is to feed poor Muslims. Thus we can see that this subject covers a wide and important area of Islamic Shariah.
Foods can be primarily divided into two sections:
1. Plants, fruits, vegetables and grains.
All these can be eaten as long as they are not harmful to human beings. This means that they must not contain poisonous or narcotic substances.
2. Living creatures.
These can be divided into three:
a) Those that live in the sea.
b) Those that live on the land.
c) Birds.
a) Sea creatures.
We are allowed to eat any fish as long as it has scales. All other sea creatures such as whales, sharks, turtles, lobsters and crabs are Haraam. The only exception is for prawns and shrimps, which can be eaten.
In order for the fish to be Halaal, it must be removed alive from the water. It does not matter who has done the fishing or what method has been used to catch the fish.
b) Land creatures.
This term covers all animals that live on the face of the earth. Allah has permitted the eating of some and forbidden others. The first five verses of Suratu Ma'idah (Sura no. 5) give a summary of the commands regarding what is permitted to eat.
Amongst domestic animals, camels, cows, goats and sheep are permissible to eat. They all possess a hoof or cloven hoof. From amongst wild animals, which means animals which are not normally kept in enclosures, mountain sheep, wild cows and asses, gazelles and deer are permitted.
It is Makruh (undesirable) to eat the meat of a horse, donkey or mule.
It is not permitted to eat the meat of animals that possess canine teeth or fangs. Examples of such animals that are sometimes eaten by man are dogs, rabbits, elephants and monkeys. There are specific verses in the Holy Qur'an forbidding the eating of a pig.
It is not permitted to eat reptiles such as snakes and tortoises. Insects such as fleas and lice are also forbidden. However, locusts are permissible.
c) Birds.
Birds that comply with the following two conditions can be eaten.
1. The body is covered with feathers.
2. They are not classes as birds of prey (possessing talons).
There are two other principles by which one can distinguish between birds which are permitted and those that are not.
1. Every bird which, when in flight glides more than the flapping of its wings cannot be eaten.
2. If a particular bird's movement is not known, then before eating one must check for the presence of one of the following: a craw (where grain collects in the throat), a gizzard (part of the stomach) or a projection (a fork-like extension on the bird's foot which performs the function of a talon).
Thus chickens, turkeys, pigeons and all small birds are permissible to eat. Even ostriches and peacocks are allowed.
Birds of prey like eagles, hawks and vultures are Haraam to eat. Crows, rooks and ravens should not be eaten either.
Other animals which fly but are not classified as birds such as bats, bees and other flying insects are Haraam.
Note that in cases where one is in danger of dying through starvation, anything, including forbidden things, can be consumed to save life. However, this must be done as a last resort and only the absolute minimum must be eaten.
Slaughtering according to Shariah.
All animals and birds that are permissible to eat are nevertheless forbidden to a Muslim unless they have been correctly slaughtered. The laws for hunting differ slightly and can be obtained from books of Islamic Laws of various jurists.
The correct method of slaughtering involves the simultaneous cutting of the gullet, windpipe, carotid artery and jugular vein of the animal with a sharp knife. The conditions for the slaughtering are as below:
The one who carries out the slaughtering must be a Muslim.
If possible, the instrument used to slaughter should be made of iron.
The creature to be slaughtered must be made to face the Holy Ka'aba.
The person performing the slaughter must mention the name of Allah as he slaughters the animal.
There must be a normal emission of blood from the animal after the slaughter.
The animal must show some sign of movement after being slaughtered, especially if there was some doubt whether the animal was alive before being slaughtered.
Alcohol
Allah says in the Holy Qur'an:
"They ask you about wine and gambling. Say: in both these there is great sin and also (some) profit for men; but their sin is greater than their profit..." (al Baqarah, 2:219)
"The Shaitan only desires to cause enmity and hatred to spring in your midst by means of intoxicants and games of chance, and to keep you off from the remembrance of Allah and from prayer. (al Ma'idah, 5: 90)
Imam Ali ar-Reza (A) says:
"Allah has prohibited liquor on account of the evils resulting from it and because it renders reason and intellect of no effect and destroys 'Haya' - modesty and sense of shame."
The following sayings are by Imam Ja'far as-Sadiq (A) and also repeated by other Imams (A):
"Do not associate with drunkards because as and when calamity befalls upon them, it will also engulf their associates (friends)"
"One who sits at a dining place at which others drink liquor is cursed (by Allah)"
In modern society alcohol is the most dangerous legal drug. Under its influence, man is not only a danger to himself, but to those around him also.
While it is accepted universally that excess alcohol is harmful, it is thought that in moderate amounts it can be beneficial. Islam totally forbids the consumption of alcohol in any amount. It also forbids Muslims from any involvement in its production, distribution or sale.
The greatest gift of Allah to humans is their ability to reason. This distinguishes us from all other creatures. Without our ability to reason, we become no different from the animals. It is because alcohol destroys this faculty of reason that it is Haraam.
Imam Ja'far as-Sadiq (A) says:
"Alcohol is the root of all evils and sins. A person who drinks alcohol loses his sanity. At that time, he does not know Allah, does not fear committing any sin, respects the rights of no one and does not desist from committing evil openly. The spirit of piety and faith departs from him and only the impure and vicious spirit, which is far off from the Mercy of Allah, remains in his body. Allah, His angels, His prophets and the true believers curse such a man, and his daily prayers are not accepted for forty days. On the Day of Judgement his face will be dark, his tongue will come out of his mouth and saliva will fall on his chest and he will desperately complain of thirst."
To eat at a table where alcohol is being served is Haraam.

Guidelines to eating at restaurants
When eating out it is important to establish who owns the restaurant. If it is owned by a Muslim who apparently is mindful of the religion then no further investigation is necessary and all food served is Halaal.
If it is owned by a Muslim who appears to be unmindful of the religious laws, for instance he serves or allows alcohol on the premises, then he must be questioned about the source of his meat, the handlers of the food and its contents. You can eat there only if you are certain that it is Halaal.
According to Agha Seestani, Christians and Jews can be considered to be Pak, and food prepared by them can be eaten by his Muqalideen.
If a restaurant is owned by a non Muslim or ownership is unknown, then the meat cannot be eaten, unless one becomes convinced that it is Halaal and has been cooked by a Muslim, Christian or Jew.
As regards vegetable products, the method of preparation has to be checked. For instance, when buying chips, one has to ask the owner whether the oil used for frying is vegetable oil and whether meat products are fried in the same oil.
Products that are advertised as suitable for vegetarians or fish based products like cod burgers are Halaal, unless one is sure that the contents include animal products or that they have been handled by people other than Ahle Kitaab i.e. Muslims, Christians and Jews.

Eating Manners
There are certain acts that are encouraged when taking a meal:
1. Washing of the hands before eating.
2. Washing hands and drying with a dry cloth after eating.
3. To recite the name of Allah (Bismillah) before eating.
4. The host should begin eating first and end last.
5. To eat with the right hand.
6. To take small bits of food and chew thoroughly.
7. To collect and eat the bits of food scattered on the dining cloth.
8. To take salt before and after the meal.
There are certain acts that are discouraged when taking a meal:
1. To eat when not hungry.
2. To over-eat.
3. To gaze at others while eating.
4. To eat food while it is very hot.
5. To blow on food or drink to cool it.
6. To throw a fruit before one has fully eaten it.
7. To scrape off meat from a bone in such a manner that nothing remains on it.
8. To peel those fruits which are normally eaten with their skins.